Apparatus for changing crankcase oil



Nov. 9, 1965 o. G. LEWIS APPARATUS FOR CHANGING CRANKCASE OIL 6Sheets-Sheet l Filed Feb.

mDwE lill Oliver G. Lewis mvenfor By Cecil C. Schmid? Agen Nov. 9, 1965o. G. L Ewxs APPARATUS FOR CHANGING CRANKGASE OIL 6 Sheets-Smet 2 FiledFeb.

@mommy @00 FIGURE 2 Oliver G. Lewis Inventor By Cecil c. Schmidt AgentNov. 9,` 1965 o. G. LEWIS 3,216,527

APPARATUS FOR CHANGING CRANKCASE OIL Filed Feb. l, 1963 6 Sheets-Sheet 3FIGURE 5 FIGURE 3 FIGURE 4 Oliver G. Lewis Inventor By Cecil C. SchmidtAgent Nov. 9, 1965 o. G. LEWIS APPARATUS FOR CHANGING GRANKCASE OIL 6Sheets-Sheet 4 Filed Feb.

Oliver G. Lewis Inven'for By Cecil C. Schmidt Agent Nov. 9, 1965 o. G.LEWIS APPARATUS FOR CHANGING CRANKCASE OIL 6 Sheets-Sheet 5 Filed Feb.

[ I DRAIN ADD REFILL I L SWITCH 44 ANTITY SELECTOR 7 OIIver G. LewisInventor FIGURE By Cecil C. Schmidt Agent Nov. 9, 1965 o. G. I Ewxs3,216,527

APPARATUS FOR CHANGING CRANKGASE OIL Filed Feb. l, 1965 6 Sheets-Sheet 6DRAIN PB.

VACUUM PUMP BRIDGE RECTIFIER HO VOLT AC POWER SUPPLY Oliver G. Lewisinvenor FIGURE 8 By Cecil C. Schmidt Agent United States Patent O3,216,527 APPARATUS FoR CHAYGING CRANKCASE ouJ Oliver G. Lewis,Westfield, NJ., assigner to Esso Research and Engineering Company, acorporation of Delaware Filed Feb. l, 1963, Ser. No. 255,594 Claims.(Cl. 184--l.5)

This application is a continuation-in-part of my copending applicationSerial No. 230,868, now abandoned, -led October V16, 1962.

This invention relates to a method and apparatus for draining usedlubricating oil from a lubricant holding case and for subsequentlyadding new oil to said case.

THE PROBLEM The conventional method for replacing used oil in thecrankcase of an internal combustion engine mounted in a motor vehicle isto first drive the vehicle, eg., automobile, onto a hydraulic lift andelevate it to a height several feet above the ground. It is thennecessary for a mechanic to crawl or walk under the automobile andremove the drain plug presently used to close the bottom of thecrankcase. The oil is allowed to ilow from the crankcase into a suitablereceptacle. The drain plug is then manually replaced and the automobilelowered. The cap on the crankcase ll pipe is removed and a pre-selectedquantity and quality of new motor oil is manually added to the crankcasevia the fill pipe. This conventional method for replacing used oil inthe crankcase of an internal combustion engine has numerousdisadvantages, including the requirement for a hydraulic lift or oilpit, the length of time required, the possibility of crossthreading thedrain plug, the length of time that an operators presence is required,and the accompanying mess. More importantly, conventional drainingtechniques leave a sizable quantity of oil remaining in the crankcase.Because conventional draining is incomplete, sludge and foreignparticles often remain in the crankcase.

Numerous attempts have been made to develop suitable devices fordraining used oil from the crankcases of motor vehicles but none havebeen entirely successful.

These prior art devices, each an apparent advance in the art at theirparticular point in time, are represented by the following U.S. patents:Nos. 1,609,697; 1,659,019; 1,666,992; 1,815,221; 1,841,505; 1,886,098;1,962,623; 2,105,761; 2,216,360; 2,206,992; 2,477,450; 2,552,749;2,603,312; 2,612,289; and 2,635,550.

These previous attempts at oil removal suffered from variousdeficiencies. In some cases, the amount of equipment (and cost thereof)to be permanently attached to each automobile was prohibitive. Somedevices were so complex that even though they had some definiteadvantages they were not commercially accepted because it was easier forthe service station attendant to perform the old manual drainingtechniques. Still other devices were so bulky and expensive that theywere not acceptable. Moreover, most of these devices only drained theoil and manual techniques still had to be employed to add new oil.

An added ditiiculty in developing a device to be used in commercialservice stations is that automobile owners are ultra-conservative. Theyare so accustomed to the practice of having the used oil drained fromtheir automobile engines through the drainage outlet in the Ibottom ofthe crankcase that the vast majority are skeptical of the ability of anydevice to effectively remove the used oil from the crankcase. Mostcustomers want to know that the oil has been removed and they want todecide this fact for themselves. They normally will accept the word of amechanic or the indication of a ma- 3,2i6,527 Patented Nov. 9, 1965 ICCchine, unless they can actually watch the oil removal being performed.

THE INVENTION A method and apparatus for overcoming many of thedeficiencies of the prior art systems has now been discovered. Thepresent invention involves broadly the method and apparatus forautomatically withdrawing used oil from the crankcase of an internalcombustion engine by suction and automatically adding new oil, underpressure, to the crankcase. The apparatus is designed so that thecustomer has a visual indication of the condition of the used oil whichhas been removed from his automobile. An additional feature of thepresent invention resides in the fact that the apparatus is furtherdesigned to give the customer a visual indication of the quantity andquality of the new oil which is to be added to the crankcase of hisautomobile. These two visual means are so located that the customer canvisually compare the quantity and quality of the new and used oils. Byelectronicaily actuating the apparatus, the used oil can be withdrawnfrom the crankcase, new oil can be measured out, a visual comparisonmade by the customer between the new and the used oil, and the new oilcan be automatically added to the crankcase. A feature of the presentinl vention which is of consider-able importance is that the cycle ofthe `draining and filling operations, as well as the degree of drainage,is controlled by the Aapparatus and cannot be ,altered 4by the operatorexcept through limited controls.

The present device is thought to be unique in that it is compact (muchsmaller than a conventional gasoline pump), easy to operate, isextremely fast, is not prohibitively expensive, is essentially troublefree, and requires the permanent installation of a very minor amount ofinexpensive equipment on the motor vehicle itself. Moreover, these minorchanges to the vehicle are easily incorporated during the originalmanufacturing process at a nominal cost.

The present invention will be more clearly understood by reference tothe following detailed description taken in connection with theaccompanying drawings in which:

FIGURE l is a block diagram of the electronic oil changer of the presentinvention,

FIGURE 2 is a right perspective View of an electronic oil changerconstructed according to the teachings of the present invention,

FIGURE 3 is a side view of a connecting device which can be used toconnect the flexible hose of the electronic oil changer to an oilevacuation tube,

FIGURE 4 is a front view, partly in section, of a crankcase having adrain plug type evacuation tube installed thereon,

FIGURE 5 is a front view, partly in section, of a crankcase having aWall-type evacuation tube installed thereon,

FIGURE 6 is a diagrammatic view of the oil changer of the presentinvention and FIGURES 7 and 8, taken together, are a schematic diagramof the control system of a preferred embodiment of the presentinvention.

GENERAL DESCRIPTION AND OPERATION Referring now to FIGURE l, the hood ofan automobile (not shown), for example, is raised and a flexible hose l,attached to the electronic oil changer, is then placed in communicationwith the lower reaches of the automobile crankcase in a manner as willbe later described. The service station attendant then selects thequantity and quality of the new oil to be charged into the engine. Thisis done through dials located on the control panel (not shown) of theelectronic oil changer. The attendant may then, for example, depress abutton (not shown) on the electronic oil changer marked automatic In theelectronic oil changer, a vacuum is produced in the transparent used oilcylinder 3 by some convenient means (e.g., electric vacu'um pump 2).This vacuum draws the used oil from the crankcase (not shown) throughflexible hose 1 into the transparent used oil cylinder 3 where thecustomer may see it. Meanwhile, the previously selected quality andquantity of new oil is being automatically metered by an automaticmetering device 4 (e.g., constant displacement cylinder) into a secondtransparent cylinder (new oil cylinder 5) where the customer may make adirect comparison between the sparkling new oil and his dirty used oil.It should be realized that once the oil quality, e.g., oil quality #3,has been selected only its corresponding metering device 4 will be inoperation. The metering devices related to the other oil qualities willbe idle. The quantity metered out by the automatic metering device 4 maybe in increments of one pint or less if desired.

By the term vacuum as used throughout this specification, it is intendedthat zero inches of Hg will correspond to no vacuum at all (normalatmospheric pressure) and that a vacuum of 29.92 inches of Hgcorresponds to a perfect vacuum, i.e., zero p.s.i.a. Thus a reduction invacuum is intended to denote an increase in absolute pressure.

As the major portion of the used oil is drawn from the crankcase (notshown) by the vacuum, air is drawn into the used oil cylinder 3 from thecrankcase and rapidly reduces the vacuum within used oil cylinder 3.This sudden burst of air from the crankcase through flexible hose 1 intoused oil cylinder 3 is effective in removing bits of foreign materialsfrom the crankcase, e.g., sand, metal chips, etc. As the vacuum drops toa predetermined level of from 2 to 12 inches Hg, e.g., 4 to 10 inchesHg, a timing cycle starts and allows a number of seconds, usually fromto 60 seconds, e.g., l5 to 30 seconds, of continued pumping to collectthe remaining oil from the crankcase. It is to be noted that this timingcycle does not start until the major portion of the used oil has beenwithdrawn from the crankcase and the nal volume of used oil remaining inthe crankcase is not, therefore, dependent on the temperature andviscosity of the oil or the total quantity of oil torbe removed. As soonas the timed cycle has been completed, thus indicating the oil removalcycle to be complete, the electronic oil changer will automaticallycause the new oil to be forced from the new oil cylinder 5 intothe'crankcase via the flexible hose 1 without further attention from theoperator. This addition of new oil to the crankcase is done by means ofair pressure from source 6. Suitable valves will prevent the entry ofnew oil into used oil cylinder 3. After the new oil has been deliveredto the crankcase, the system will automatically eliminate the used oilfrom used oil cylinder 3 into a suitable receptacle (slop oil tank 7) bymeans of air pressure from source 6 and then shut off. Indicator lightsmay be mounted on the electronic oil changer to show the customer thequantity and quality of oil charged to the engine.

VIf desired, the electronic oil changer may be set, e.g., by dialingzero quantity of new oil, to remove used oil and then stop after theused oil has been removed. At this point new oil may be selected andadded to the crankcase or, if desired, the used oil may be returned tothe engine merely by pressing a Refill button on the control panel.

FIGURE 2 is a right perspective view of a portable electronic oilchanger that has been constructed according to the present invention.The cabinet 8 houses the necessary relays, vacuum pump, constantdisplacement pumps for' metering new oil, wiring, etc. Transparentcylinders 3 an-d 5 are employed for used oil and new -oil respectivelyand may have a capacity of from 6 to 12 quarts or more. Use of thesecylinders is contemplated where individual customer appeal is required.When captive customers are encountered (taxi fleets, etc.) they are notneeded. The control switches 9 are used to signal the electronic oilchanger to drain the used oil, to add new oil, to rell the crankcasewith the used oil that has been previously withdrawn, to operateautomatically, or to reset the entire apparatus. Dial 10 is used toselect the quality of the new oil, i.e., grade of oil, and dial 11 isused to select the quantity of new oil to be measured out into new oilcylinder 5 prior to being added to the crankcase. Pressure gage 12indicates the pressure, e.g., air pressure, used to force the new oilinto the crankcase from new oil cylinder 5 during the filling operation.This pressure will usually be from 2O to 100 p.s.i.g., although otherpressures may be used, eg., 40 to 80 p.s.i.g. Pressure gage 13 indicatesthe pressure used to feed the quality grade of new oil selected to itsassociated constant displacement metering device or pump 4 (not shown)which meters the selected grade of new oil with a high degree ofprecision. This oil feed pressure may range from 20 to l0() p.s.i.g.,although pressures of 40 to 8O p.s.i.g. are most frequent. Vacuum gauge14 indicates the vacuum applied to used oil cylinder 3 in drawing theused oil from the crankcase The vacuum will usually be from 20 to 29inches Hg, e.g., 24 to 28 inches Hg. A bank of lights 15 may be used toindicate to the customer and/or operator the quantity of new oil thathas been added to new oil cylinder 5 (e.g., one light may be illuminatedper each one pint increment of new oil). Additionally, transparentcylinders 3 and 5, when used, may be graduated. Flexible hose 1 of someconvenient length, eg., 3 to l0 feet, and of an internal diameter offrom about 1A" to 1/2, e.g., about 3%", is connected to an internalmanifold (not shown) within the electronic oil changer which is, inturn, connected to transparent cylinders 3 and 5. At the free end of theflexible hose 1 is a connector 16 of the type shown in FIG- URE 3. Thisconnector should be of the quick-connect type and capable ofwithstanding the pressure of new oil being forced into the crankcase, aswell as withstanding the vacuum during oil withdrawal. This connector 16is used to connect exible hose 1 to an evacuation tube mounted in or onthe crankcase. When, however, used oil is to be withdrawn from acrankcase Via the oil ll pipe or the oil measuring stick guide tube, theconnector 16 can be used to connect exible hose 1 to a tube or wand thathas been inserted into one of those openings. Preferably, the evacuationtubes as hereinafter described are employed. Input tubes 17 and 18 areused to feed the new and used oil into cylinders 3 and 5 and may containcheck Valves to prevent back ow or contamination between differentqualities of oil.

-FIGURE 3 illustrates in detail a connecting device (e.g., connector 16of FIGURE 2) which can be used to rapidly join the flexible hose 1 ofthe electronic oil changer to the upper end of an evacuation tube, wand,etc. A connector of the type shown is manufactured by MechanicalProducts Corporation, 1716 West Hubbard Street, Chicago 22, Illinois. Inoperation, lever 16a is depressed and the end of an evacuation tube,wand, etc., is inserted into the open end of connector 16. Lever 16a isthen released and a leak-free connection is formed.

FIGURE 4 illustrates a drain plug-type evacuation tube which can be usedwith present day automobiles in cooperation with the present invention.The plug 19, itself, resembles a normal drain plug and its threaded endis hollow (19a) for part of its length in an axial direction. It isprovided with one or more lateralports 19b. It is passed through anannular member 20 (e.g., made of nylon, etc.) and screwed into thenormal drainage outlet of crankcase 21. Thus, oil contained in thecrankcase 21 can, under the influence of the automatic oil changer, flowdown through the hollow portion 19a of plug 19, out the lateral ports1911, through annular member 26 and on to the oil changer (not shown inthis view) via tube 23 as shown by the arrows. During oil changingoperations, the flexible hose 1 of the oil changer would be connected totube 23 by means of a connecting device, eg., connector 16. Generallytube 23 will have an inside diameter of about 1A to 1./z, although thinwalled S/" tubing is preferred. At the present time, it is believed thatve sizes of drain plugs will accommodate all mass produced American carssince 1950, with the possible exception of the Hudson.

FIGURE 5 illustrates a wall-type evacuation tube as it might appear ifit were part of the manufacturers installed equipment. An opening is cutin the wall of crankcase 21 and a rigid tube 26 is insertedtherethrough. Tube 26 will generally have an inside diameter of about 1Ato 1/2 inch although use of thin walled (e.g., 0.040 or less) 3/s inchO.D. tubing is preferred. One end of tube 26 rests on the oor ofcrankcase 21 at its lowest point. The lower end of tube 26 is contouredto rest against the bottom of crankcase 21 at its lowest point. Thecontoured end of dip leg 26 is notched to provide a lateral area open tothe oil which is approximately equal to the inside cross-sectional areaof tube 26. Preferably, the maximum height of the notches 25a in the endof tube 26, above the floor of crankcase 21', will be no more than 0.15inch and preferably not less than 0.080 inch. This allows substantiallyall of the oil held in crankcase 21' to be withdrawn by suction createdin tube 26. Tube 26 is aiiixed to the wall of crankcase 21' at point 25by some suitable technique, e.g., welding. One end of a ilexible tube23' is attached to the uppermost end of tube 26 and the other end is eX-tended to a point above the normal oil level 22 in crankcase 21. Whennot in use, tube 23' may be closed by some suitable device 24, eg., aplastic snap cap.

According to the present invention, an evacuation tube, such as one ofthose shown in FIGURES 4 or 5, is attached to a lubricant containingcase 21, e.g., a crankcase. The exible hose portion (e.g., 23 or 23) ofthe evacuation tube is extended into the upper engine compartment,terminating at a point well above the normal oil level 22 within thecrankcase 21.

By far the most satisfactory method for removing used oil is through thewall-type evacuation tube as shown in FIGURE 5. Alternatively, however,the other types of evacuation tubes may be used and, in some instances,oil may be withdrawn via a flexible hose or wand inserted into the oilfill pipe or oil measuring stick guide tube.

DETAILED DESCRIPTION AND OPERATION The detailed description and sequenceof operation which follows is made with specific reference to FIG- URES6, 7, and 8 which should be read simultaneously.

FIGURE 6 is a diagrammatic view of a preferred embodiment of the presentinvention while FIGURES 7 and 8, taken together, are a schematic diagramof a control system for such `an oil changer. For ease in reading theiigures, the following reference symbols have been used.

L-line LLS-lower limit switch M-micro P-pressure PB-push button RL-relaySV-solenoid valve SVV-switch TD-time delay ULS-upper limit switchV-vacuum The several hourglass shaped contacts shown in verticalalignment above each element, eg., relay of FIGURE 7, correspond to theelectrical contacts of their related element. For example, three (3)contacts are shown (by the dotted line), which also indicates that thecontacts are ganged, to correspond to relay 35. The upper Contact isshown in a normally open position (as regards the circuit); the centercontact is shown in a normally closed position (as regards the circuit)and the lower contact is not being used at all. The black portion of thehour-glass shaped contacts thus represents the conductive position whilethe White portion represents the non-conductive position. Once a relayis energized, the black and white portions will reverse themselves.Three contacts have been shown for all relays since many commerciallyavailable relays have that number of contacts. In accordance withconventional electrical drawing practice, FIGS. 7 and 8 show the contactpositions of each of the relays in the power oif or uncnergized state.It will be understood that when in the normal sequence of operation arelay or push button, etc. is actuated, its associated contacts will alltransfer from the electrical state shown in FIGS. 7 and 8 to an oppositeelectrical state. It will also be understood that this transfer ofelectrical state is effected by the simultaneous transfer of all threecentral moving contacts of each relay from their indicated position inelectrical contact with the lower black normally closed contact intocontact with the upper white normally open Contact.

It is assumed, in the following description, that the hose 1 of theelectronic oil changer of FIGURE 6 has been suitably connected to thelower reaches of a crankcase of a motor vehicle.

NORMAL SEQUENCE (l) Select the desired quantity and quality of new oilto be added to new `oil cylinder 5. This selection is made by means ofquantity selector switch l1 and quality selector switch 10. Theselection of oil quality, e.g., a premium grade motor oil, throughquality selector switch 10 will activate the corresponding oil meteringdevice 4 (e.g., constant displacement cylinder) with its attendant oilcontrol solenoid valve 4t), control valve 43, and upper and lower limitswitches 38 and 42, respectively. Thus if the quality of new oilselected by quality selector switch 10 was that represented by theextreme left postion shown in FIG. 8, only one set of upper and lowerlimit switches (38 and 42) would be employed and all the remaining upperand lower limit switches ULS 3S and LLS 42 and their associated solenoidvalves SV 4G shown in brackets would be idle. Metering stepping switchMis used to cause the measurement of new oil to be halted when theselected quantity of new oil has been added to new oil cylinder 5.

(2) Press automatic push button switch 27 to close its normally opencontact points.

(3) Relay 2S and time delay relay 29 are thus placed in parallel acrosslines L-36 and L-73 and energized and latched (i.e., maintainedenergized) through the uppermost set of normally closed holding pointsof relay 30 (reset relay) until such later time that relay 30 isenergized.

(4) The operation of push button switch 27 is also eiectlve to connectthe hot side (L-36) of the power supply to the vacuum pump 2 andsolenoid valve 31 which are energized via the normally closed lowerrnostcontact on RL-32. Once the push button 27 is released the pump 2 andvalve 31 remain connected to the line L-36 through the normallly openuppermost contacts of relay 28 and the normally closed uppermost contactpoints lon relay 30.

(5) Three-way valve 33 is in position A so that used ci il csomingthrough line 1 will be fed into used oil cylin- (6) Relay 34 isenergized through relay 35 and is latched to line 36.

(7) Solenoid valve 31 opens to allow the vacuum to be applied to usedoil cylinder 3 and vacuum switch 37.

(8) The normally open Contact on time delay 29 allows vacuum switch 37to build up vacuum and open its contact.

(9) The circuit through the upper limit switch 38 activates relay 39 andsolenoid valve 40. Solenoid valve 40 remains locked into position untiloil pressure on top of measuring piston 41 forces the measuring piston41 downward and trips lower limit switch 42 releasing relay 39 andclosing solenoid valve 40.

(10) When solenoid valve 40 is closed, the ow of new oil through controlvalve 43 is changed and the new oil then flows up against the bottom ofmeasuring piston 41 forcing it upward against upper limit switch 38.This causes the discrete quantity of oil above measuring piston 41 to beforced out into new oil cylinder 5.

(l1) If the quantity of new oil required by quantity selector switch 11(as modied by metering stepping switch 44) has not been satisfied, upperlimit switch 38 will continue to yclose the circuit to re-energize relay39 and solenoid valve 40 and steps 9 and 10 supra will be repeated untilthe desired quantity of o'il has been provided.

(l2) When the quantity selected by quantity selector switch 11 has beensatisfied, the circuit through upper limit switch 38 and selector switch11 will energize relay 35, deenergizing relay 39 and solenoid valve 40will remainv closed.

(13) As the major portion of the used oil is drawn from the crankcaseVia line 1 through valve 33 into used oil cylinder 3, air, from thecrankcase, entering used oil cylinder 3 will cause the vacuum to reduce(increase in pressure).

(14) As the vacuum drops to 6 inches of mercury, Vacuum switch 37 closesand activates time delay 45 through relay 46.

(15) Time delay 45 allows the vacuum pump 2 to continue pumping forseconds to remove the last of the used oil from the crankcase and toclear hose 1.

' (16) As time delay 45 times out, it will act through relay 35 andenergize relay 32, time delay 47, solenoid valve 48, and solenoid valve49.

(17) Activation of relay 32 stops vacuum pump 2, deenergizes solenoidValve 31, and completes the D C. circuit to energize relay 50. Timedelay 45, acting through relay 28, latches in relay 51.

(18) Valve motor 52 is energized by relay 50 and turns cam 53 untilmicro switch 54 is Iopened and drops out relay 50 with valve 33 isposition B, thus connecting the crankcase to new oil cylinder 5 via line1.

(19) As micro switch 54 is opened solenoid valve 48, solenoid valve 49,relay 32 and time delay 47 will be energized since the oil measuringdevice 4 has completed its metering job `and metering stepping switch 44has completed its sequence. This connects the line air pressure 6 (e.g.,30 p.s.i.g.) to the top of the new oil in the new oil cylinder 5 andforces the previously measured new oil from cylinder through valve 33and line 1 into the crankcase. (20)V Time` delay 47 prevents the actionof pressure switch 55 until the pressure builds up within new oilcylinder 5. Pressure switch 55 opens before the time out of time delay47.

(21) As all of the new oil within cylinder 5 is discharged, the pressurewithin the cylinder will fall. When the pressure reaches 5 p.s.i.g.,time delay 47 and the closing of the contact on pressure switch 55 willactivate relay 30 which drops out relay 51 and latches in relay 56.

(22) Relay 56 will then activate valve motor 52, which turns cam 53causing micro switch 57 to open (with Valve 33 in position A).

(23) The metering stepping switch 44 is energized through relay 56 andresets for the next cycle. When the metering stepping switch reacheshome, it drops out relay 35 which drops out relay 32, defenergizingsolenoid valves 48 and 49.

RETURNING USED OIL TO THE `CRANKCASE (l) Press refill push button switch58.

(2) Relay 59 will be energized and latch in through micro switch 69. TheValve motor 52 will be energized and turn cam 53 until micro switch 60is opened, dropping out relay 59 with valve 33 in position C.

(3) Relay 61 will be energized opening solenoid valves 62 and 63.Solenoid valve 64 and time delay 65 are also energized through relay 61.

(4) Line air introduced into used oil cylinder 3 through solenoid valve62 will force the used oil through solenoid valve 63 to valve 33 whichis in position C and on to the crankcase Via line 1.

(5) As the pressure in used oil cylinder 3 drops to 5 p.s.i.g. (due toall of the oil being discharged) pressure switch 66 acting through timedelay 65 will energize the reset relay 39. Reset relay 30 drops outrelay 51 and latches in relay 56.

(6) Valve motor 52 is energized by relay 56, turns cam 53, causing microswitch 57 to open with valve 33 in position A. Metering stepping switch44 is energized through relay 56 and resets for the neXt cycle. When themetering stepping switch 44 reaches home, it `drops out relay 32de-energizing solenoid valves 48 and 49.

ADDING NEW OIL WITHOUT FIRST DRAINING USED OIL (l) Select the quantityand quality of oil by means of switches 10 and 11.

(2) Press the add oil push button switch 67.

(3) Relay 51 is latched in. Relay 34 is energized and latches throughrelay 35 to L-36. y

(4) Relay 34 activates relay 39 and solenoid valve 40 through upperlimit switch 38. Solenoid valve 40 remains in position until the oilpressure on top of measuring piston 41 forces the measuring piston 41downward and trips lower limit switch 42 releasing relay 39 and closingsolenoid valve 40.

(5) When solenoid valve 40 is closed, the flow of new oil throughcontrol valve 43 is changed and the new oil then flows up against thebottom of measuring piston 41 forcing it upwardly against upper limitswitch 38 This causes the discrete quantity of oil above measuringpiston 41 to be forced out into new oil cylinder 5.

(6) If the quantity of new oil required by quantity selector switch 11has not been satisii'ed, upper limit switch 38 will continue to closethe circuit and steps 4 and 5, supra, will be repeated until the desiredquantity of new oil has been provided.

(7) When the quantity of oil selected by quantity selector switch 11 hasbeen satisfied, the stepping switch 44 closes the circuit through relay34, metering stepping switch 44, quantity selector 11 and relay 46, thusstopping the measuring sequence and latching in relay 35.

(8) Relay 35 energizes relay 32, time delay 47, and solenoid valves 48and 49.

(9) Activation of relay 32 energizes valve motor 52 through relay 5 0.Valve motor 52 turns cam 53 until mioroswitch 54 is opened and relay 50drops out with valve 33 in position B.

Y (10) Air enters new oil cylinder 5 through solenoid valve 48. The newoil is then forced from new oil cylinder 5 to the crankcase via line 1in the manner as previously described with reference to the NormalSequence.

(lil) As the new oil is discharged from new oil cylinder 5, the pressurewithin the cylinder will drop. When the pressure reaches 5 p.s.i.g. timedelay 47 and pressure switch 55 will activate relay '30, dropping outrelay 5'1 and latching in relay 56.

(12) Valve motor 52 will be energized by relay 56 and turn cam 53 untilmicroswitch 57 is opened with valve 33 in position A. The meteringstepping switch 44 is energized through relay 56 and resets for the nextcycle. As the stepping switch 44 reaches home it drops out relay 35which drops out relay 32 thus de-energizing solenoid valves 48 and 49.

Used oil is drained from used oil cylinder 3 by pressing the drain pushbutton switch 68 which allows the line air pressure to enter the top ofused oil cylinder 3 and force the used oil through solenoid valve 64 toslop oil 7. Reset push button switch 69 is used to reset the electronic.29 changer, at any point in its operation, to its initial staticposition. The various rectiiiers (7G and 71) resistor 72 and capacitor73 are used to provide the necessary electrical requirements for thesundry relays, motors, etc. More specically, rectifier 7l supplies D.C.power for the D.C. relays and metering stepping switch 44. Rectifier 70is a gating mechanism to allow D.C. relay 56 to only latch in when apositive pulse is received. Relay 30, on the same circuit, will latch inon either a positive or negative pulse. Resistor 72 and capacitor 73form a time constant to temporarily latch in relay Si) until it islatehed in by microswitch 54. It then olers no further holding power.

EXAMPLES The present invention will be more clearly understood byreference to the following examples which include a preferredembodiment.

Example 1 A completely self-contained apparatus substantially asdescribed has been constructed for experimental purposes and tested on anumber of automobiles on which evacuation tubes of the types shown inFIGURES 4 and 5 had been mounted. In the device, as constructed, aninitial vacuum of 27 inches Hg was employed for draining the used oiland a 20 second time cycle was set to begin when the vacuum haddiminished to 7 inches Hg. A pressure of 60 p.s.i.g. was used inintroducing the new oil to the constant displacement cylinder 4 used formetering the new oil into the new oil cylinder 5. Air pressure of 30p.s.i.g. was applied to force the new oil from the new oil cylinder intothe crankcase 21. It was found that, with a thin walled evacuation tubehaving a 3/8 inch outside diameter, used oil (at 125 F.) could beremoved at the rate of l lpint in every 51/2 seconds. It was found thatthe hood of an automobile could be raised, the ilexible hose 1 from theelectronic oil changer connected to the evacuation tube, the quantityand quality of new oil selected, 4 quarts of used oil removed from thecrankcase 21 and 4 quarts of new oil added to the crankcase 21 in just lunder 2 minutes.

Numerous tests were conducted using the apparatus just described and itwas determined that the oil removal via this electronic oil changerwould, in all tested cases, equal or exceed the extent of oil removalvia the normal drain plug technique. Typical quantities of residual usedoil found in crankcases after evacuation with the electronic oil changerwhen used in conjunction with an evacuation tube of the type shown inFIGURE 5 were on the order of 5 cc. In most automobiles it was possibleto exceed the oil removal possible through conventional draining by from100 to 60() cc. An example of such a situation was found in a 1959Lincoln where the drain plug is located part way up the side of thecraukcase, thus allowing approximately 570 cc. of oil to remain in thecrankcase after conventional draining. By installing the wall-typeevacuation tube as shown in FIGURE 5 and using the electronic oilchanger, it was possible to reduce this quantity of residual oil toabout 5 cc. Using the drain plug type evacuation tube of FIGURE 4, theoil removal is substantially the same as that obtained by conventionaldraining` Example 2 For purposes of experimentation and testing, anindustrial model of the electronic oil changer has also been constructedfor use on taxi fleets, trucks, etc., where there is no induw'dualcustomer to satisfy. Here, the equipment was modified to eliminatetransparent cylinders 3 and 5. The used oil was pumped directly to aslop tank 7 and a single grade of new oil was used. Multiple grades ofnew oil were also tested using several constant displacement cylinders4. The results produced by that industrial oil changer were essentiallythe same as these obtained with the portable model described in Examplel.

l0 The selection of commercially available counterparts of the variouscomponents used in constructing the aforementioned oil changers arebelieved to be well within the skill of the art. However, for whateverbenefit that the public may derive, the following fragmentary list ofsuitable components is provided.

Stepping switch-Clare type 20 NBR R1858 Push buttons-Honeywell Series 2Selector switch-JET #MS-ZO-Z Rectitier-Full wave, l amp, 115 v. D.C.

Relays-Potter & Bromeld KRP Time delays-Amperite Selectorswitch-Centralab Resistor-47K ohms Capacitor-12 UF 150 v.

Glass cylinders (2)-Pyrex Double Tough 6 x 18" Vacuum pump-Gast#0740-V4-Gl80X Solenoid valve-3 way diff. Skinner V54DB2075 Solenoidvalve2 way Skinner LC2DB3150 Vacuum switchMeletron DIT-H18 Gauge--15-0100# U.S. 17055 Pressure switch-Hobbs M1925 Check valve-Circle Seal#530B 2M-0.5

Measuring cylinder-Allen Air #A400-4.825

Gauge-O-# U.S. FIGURE 644 Cam-1A alum. plate Motor- New England gear, 5rpm., 66 inch, 16 torque,

Model HD1 Tubing connector-Mechanical Products TC-1304 DISCUSSION Thevacuum type of apparatus as has just been described has a decidedadvantage over the use of positive displacement pumps for oil removal.For example, it has been noted that, in new cars, sand from the variouscastings will appear in the oil during the rst tWoor three oil changes.Oil changers utilizing positive displacement pumps have been employed onnew cars and found to be ineffective after 35 to 50 oil changes due tothe extensive wear caused by this loose sand and foreign material. Nosuch problems are encountered when using the present equipment which hasbeen exhaustively tested.

The electronic oil changer may be constructed as a portable mechanism oras a permanent part of the gasoline dispensing island iixtures. As apermanent installation, only the relay cabinet, metering devices for thenew oil and the transparent cylinders need be mounted at the island. Thevacuum source, new oil in bulk, and the slop oil tank could be locatedin some central location and piped to the various islands.

Having thus described the present invention with a ce-rtain degree ofparticularity, it is to be realized that numerous other modificationsand adaptations (e.g., using the .device to remove fuel from fuel tanks,flushing, etc.) can be made within the spirit and scope of the inventionas hereinafter claimed.

I claim:

1. A sequential switching device suitable for use as automatic controlmeans in an apparatus for withdrawing used oil from a lubricant holdingcase by vacuum and thereafter adding new oil under pressure to saidcase, wherein said apparatus includes conduit means, distributing meansin communication with said conduit means, vacuum means in communicationwith said distributing means, oil supply means in communication withsaid distributing means, air pressure means cooperating with said oilsupply means, and automatic control means for said vacuum means, saidair pressure means, said oil supply means, and said distributing means,which comprises in combination (a) initiator means for activating saidvacuum means to thereby create a vacuum,

(b) a first means responsive to said initiator means for establishingcommunication between said lubricant holding case and said vacuum meansthrough l l said conduit means and said distributing' means, said vacuumthereby withdrawing used oil from said lubricant holding case,

(c) a second means responsive to the level of vacuum produced by saidvacuum means, said second means deactivating said vacuum means aftersaid vacuum reaches a predetermined level,

(d) selector means for selecting a discrete quantity of new oil,

(e) a third means responsive to actuation of said selector means formeasuring said discrete quantity of new oil,

(f) a fourth means responsive to the deactivation of said vacuum meansfor discontinuing said communication between said lubricant holding caseand said .vacuum means, said fourth means causing said distributingmeans to establish communication between said lubricant holding case andsaid oil supply means, said oil supply means including said measuredquantity of new oil,

(g) a fifth means responsive to said deactivation of said vacuum meansand responsive to said third means, said lifth means operativelyconnecting said air pressure means with said oil supply means includingsaid measured quantity of new oil, thereby forcing said new oil intosaid lubricant holding case,

(h) a sixth means responsive to the level of pressure produced by saidair pressure means, said sixth means disconnecting said air pressuremeans from said oil supply means after said pressure reaches apredetermined level,

(i) a seventh means responsive to said sixth means for resetting saidsequential switching device to a normal position.

2. A sequential switching device as defined in claim 1 which alsoincludes an eighth means selectively cooperating with said seventh meansfor resetting said sequential switching device to said normal position.

3. A sequential device as defined in claim 1 which also includes a ninthmeans selectively cooperating with said fourth and fth means toeiiectuate the addition of said measured quantity of new oil, said ninthmeans bypassing said initiator means, thereby eliminating the sequenceof operations relating to said withdrawal of used oil.

4. A sequential switching device suitable for use as automatic controlmeans in an apparatus for withdrawing used oil from a lubricant holdingcase by vacuum and thereafteraddingA new oil under pressure to saidcase, wherein said apparatus includes conduit means, distributing meansin communication with said conduit means, vacuum means in communicationwith said distributing means, oil supply means in communication withsaid distributing means, air pressure means cooperating with said oilsupply means, and automatic control means for said vacuum means, saidair pressure means, said oil supply means, and said distributing means,which comprises in combination (a) initiator means for activating saidvacuum means to thereby create a vacuum,

(b) a rst means responsive to said initiator means for establishingcommunication between said lubricant holding case and said vacuum meansthrough said conduit means and said distributing means, said vacuumthereby withdrawing used oil from said lubricant holding case,

- (c) a second means responsive to the level of vacuum produced by saidvacuum means, said second means deactivating said vacuum means aftersaid vacuum reaches a predetermined level,

(d) selector means for selecting a discrete quantity of new oil,

(e) a third means responsive to said selector means Y for Vmeasuringsaid discrete quantity of new oil,

(f) a fourth means responsive to the deactivation of said vacuum meansfor discontinuing said communication between .said lubricant holdingcase and said vacuum means, said fourth means causing said distributingmeans to establish communication between said lubricant holding case andsaid oil supply means, said oil supply means including said measuredquantity of new oil,

(g) a fth means responsive to said deactivation of said vacuum means andresponsive to said third means, said ifth means operatively connectingsaid air pressure means with said oil supply means including saidmeasured quantity of new oil, thereby forcing said new oil into saidlubricant holding case,

(h) a sixth means responsive to the level of pressure produced by saidair pressure means, said sixth means disconnecting said air pressuremeans from said oil supply means after said pressure reaches apredetermined level,

(i) a seventh means responsive to said sixth means for resetting saidsequential switching device to a normal position,

(j) an eighth means selectively cooperating with said seventh means forresetting said sequential switching device to said normal position, and

(k) a ninth means selectively cooperating with said fourth and fth meansto effectuate the addition of said measured quantity of new oil, saidninth means bypassing said initiator means, thereby eliminating thesequence of operations relating to said withdrawl of used oil.

5. An electronic oil changer for withdrawing used oil from a lubricantholding case by vacuum and thereafter adding new oil by air pressuremeans to said case which comprises in combination:

(a) conduit means,

(b) distributing means in communication with said conduit means,

(c) vacuum means in communication with said distributing means,

(d) oil supply means in communication with said distributing means,

(e) initiator means for activating said vacuum means to thereby create avacuum,

(f) a iirst means responsive to said initiator means for establishingcommunication between said lubricant holding case and said vacuum meansthrough said conduit means and said distributing means, said vacuumthereby withdrawing used oil from said lubricant holding case,

(g) a second means responsive to the level of vacuum produced by saidvacuum means, said second means deactivating said vacuum means aftersaid vacuum reaches a predetermined level,

(h) selector means for selecting a discrete quantity of new oil,

(i) a third means responsive to said selector means for measuring saiddiscrete quantity of new oil,

(j) a fourth means responsive to the deactivation of said vacuum meansfor discontinuing said communication between said lubricant holding caseand said vacuum means, said fourth means causing said distributing meansto establish communication between said lubricant holding case and saidoil supply means, said oil supply means including said measured quantityof new oil,

(k) a iifth means responsive to said deactivation of said vacuum meansand responsive to said third means, said iifth means operativelyconnecting said air pressure means with said oil supply means includingsaid measured quantity of new oil, thereby forcing said new oil intosaid lubricant holding case,

(l) a sixth means responsive to the level of pressure produced by saidair pressure means, said sixth means disconnecting said air pressuremeans from said oil supply' means after said pressure reaches apredetermined level,

(m) a seventh means responsive to said six-th means for resetting saidsequential switching device to a normal position,

(n) an eighth means selectively cooperating with said seventh means forresetting said sequential switching device to said normal position, and

(o) a ninth means selectively cooperating with said fourth and fth meansto effectuate the addition of said measured quantity of new oil, saidninth means bypassing said initiator means, thereby eliminating thesequence of operations relating to said With.

drawal of used oil.

14 References Cited by the Examiner UNITED STATES PATENTS 1,815,221 7/31Sweetland 1841.5 5 2,320,048 5/43 Parson 184-15 FOREIGN PATENTS 707,3154/54 Great Britain.

10 LAVERNE D. GEIGER, Primary Examiner.

MILTON KAUFMAN, Examiner.

1. A SEQUENTIAL SWITCHING DEVICE SUITABLE FOR USE AS AUTOMATIC CONTROLMEANS IN AN APPARATUS FOR WITHDRAWING USED OIL FROM A LUBRICANT HOLDINGCASE BY VACUUM AND THEREAFTER ADDING NEW OIL UNDER PRESSURE TO SAIDCASE, WHEREIN SAID APPARATUS INCLUDES CONDUIT MEANS, DISTRIBUTING MEANSIN COMMUNICATION WITH SAID CONDUIT MEANS, VACUUM MEANS IN COMMUNICATIONWITH SAID DISTRIBUTING MEANS, OIL SUPPLY MEANS IN COMMUNICATION WITHSAID DISTRIBUTING MEANS, AIR PRESSURE MEANS COOPERATING WITH SAID OILSUPPLY MEANS, AND AUTOMATIC CONTROL MEANS FOR SAID VACCUUM MEANS, SAIDAIR PRESSURE MEANS, SAID OIL SUPPLY MEANS, AND SAID DISTRIBUTING MEANS,WHICH COMPRISES IN COMBINATION (A) INITIATOR MEANS FOR ACTIVATING SAIDVACUUM MEANS TO THEREBY CREATE A VACUUM, (B) A FIRST MEANS RESPONSIVE TOSAID INITIATOR MEANS FOR ESTABLISHING COMMUNICATION BETWEEN SAIDLUBRICANT HOLDING CASE AND SAID VACUUM MEANS THROUGH SAID CONDUIT MEANSAND SAID DISTRIBUTING MEANS, SAID VACUUM THEREBY WITHDRAWING USED OILFROM SAID LUBRICANT HOLDING CASE, (C) A SECOND MEANS RESPONSIVE TO THELEVEL OF VACUUM PRODUCED BY SAID VACUUM MEANS, SAID SECOND MEANSDEACTIVATING SAID VACUUM MEANS AFTER SAID VACUUM REACHES A PREDETERMINEDLEVEL, (D) SELECTOR MEANS FOR SELECTING A DISCRETE QUANTITY OF NEW OIL,(E) A THIRD MEANS RESPONSIVE TO ACTUATION OF SAID SELECTOR MEANS FORMEASURING SAID DISCRETE QUANTITY OF NEW OIL, (F) A FOURTH MEANSRESPONSIVE TO THE DEACTIVATION OF SAID VACUUM MEANS FOR DISCONTINUINGSAID COMMUNICATION BETWEEN SAID LUBRICANT HOLDING CASE AND SAID VACUUMMEANS, SAID FOURTH MEANS CAUSING SAID DISTRIBUTING MEANS TO ESTABLISHCOMMUNICATION BETWEEN SAID LUBRICANT HOLDING CASE AND SAID OIL SUPPLYMEANS, SAID OIL SUPPLY MEANS INCLUDING SAID MEASURED QUANTITY OF NEWOIL, (G) A FIFTH MEANS RESPONSIVE TO SAID DEACTIVATION OF SAID VACUUMMEANS AND RESPONSIVE TO SAID THIRD MEANS, SAID FIFTH MEANS OPERATIVELYCONNECTING SAID AIR PRESSURE MEANS WITH SAID OIL SUPPLY MEANS INCLUDINGSAID MEASURED QUANTITY OF NEW OIL, THEREBY FORCING SAID NEW OIL INTOSAID LUBRICANT HOLDING CASE, (H) A SIXTH MEANS RESPONSIVE TO THE LEVELOF PRESSURE PRODUCED BY SAID AIR PRESSURE MEANS, SAID SIXTH MEANSDISCONNECTING SAID AIR PRESSURE MEANS FROM SAID OIL SUPPLY MEANS AFTERSAID PRESSURE REACHES A PREDETERMINED LEVEL, (I) A SEVENTH MEANSRESPONSIVE TO SAID SIXTH MEANS FOR RESETTING SAID SEQUENTIAL SWITCHINGDEVICE TO A NORMAL POSITION.